21002001210 has 48 divisors (see below), whose sum is σ = 56366668800. Its totient is φ = 5419870560.

The previous prime is 21002001203. The next prime is 21002001217. The reversal of 21002001210 is 1210020012.

It is an interprime number because it is at equal distance from previous prime (21002001203) and next prime (21002001217).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a junction number, because it is equal to n+sod(n) for n = 21002001192 and 21002001201.

It is not an unprimeable number, because it can be changed into a prime (21002001217) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3761010 + ... + 3766589.

It is an arithmetic number, because the mean of its divisors is an integer number (1174305600).

Almost surely, 2^21002001210 is an apocalyptic number.

21002001210 is an abundant number, since it is smaller than the sum of its proper divisors (35364667590).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21002001210 is a wasteful number, since it uses less digits than its factorization.

21002001210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7527643 (or 7527640 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21002001210 its reverse (1210020012), we get a palindrome (22212021222).

The spelling of 21002001210 in words is "twenty-one billion, two million, one thousand, two hundred ten".